Process for stiffening paper



Jan. 16, 1940.

C. G. YOUNG PROCESS FOR STIFFENING PAPER Filed Jan. 51, 1938 lnvenfor C/are G. Young ITED STATE duction of light-weight slats for Venetian blinds Patented J an.16 I

"PATENT OFFICE I PROCESS FOR STIFFENINGPAPI'IR Clare G. Young, Winnipeg, Manitoba, Canada 1 H Application January 31, 1938, serial No. 187,951

1Claim. (01. 18-56) My invention relates to improvements in proc esses .fo r stiffening paper and other flexible manufactured material principally for the pro but also for the manufacture of cartons andother articles of manufacture.

An object of my invention is-to provide means whereby flexible material such as paper, may

be stiffened economically and rendered resistant to heat, water and the efiectsjof sunshine. I

A further object of my invention is to provide in a Venetian blind, slats manufactured by the process hereinafter to be described to which will beimparted additionalstilfness by virtue of an.

arcuate or convex cross-sectional configuration.

With the above more important objects in view and such other minor objects as may appear as the specification proceeds, my invention consists essentially in the arrangement and construction of parts all as hereinafter more particularly described, reference being had to the accompanying drawing in which: I

Figure 1 is a perspective illustration of my Venetian blind. 3 v

Figure 2 is a sectional representation of the process of die-pressing the slats forming my Venetian blind.

.In the drawing like characters :of reference indicate corresponding parts in the different figures. I

The slats for Venetian blinds have hitherto been manufactured of various straightgrained woods such for example as fir, Australian gum,

ash and the like. Thesepossess the comparative disadvantage in relation to the slats manufactured by the process hereinafter described, of

1 being heavy and costly to manufacture as well as noisy when raised. Slats manufactured by my process, however, may be made for a small fraction of the cost of wooden slats, are considerably lighter in weight and do not produce the same amount of noise whenbeing raised.

In the practical carrying out of my process :for. the treatment of flexible material in the menu facturehof Venetian blind slats, I have found the best material to be red press paper which I cutto the length and width required, after which I it is submerged for fifteen minutes in a vat con- *taining a mixture of animal glue and cold water,. the. texture of the mixture being that obtained when one poundof such glue is mixed with one gallon of cold water.

I A large number of sheets sary length and size are generally placed to gether in a vat containing the foregoing mixture,

I cut to the nece.,-

after the fifteen steep the soalred sheets are placed oneby one upon a die 2, prior tobeing pressed as will later bej describedn Upon the bearing surface of the two dies between which the soaked sheets or slats are pressed, I take a sheet of board 3, cut to the length and width of 1 the slats, the said board being coated on both sides with paraflin wax. I now place upon the, board one of mysheets of soalced press, paper andabove this another wax covered board. The number of soaked press paper sheets whichare each sandwiched between the wax covered boards maybe considerable, the topmost sheet being covered also by a wax covered board against which the upper die 4 bears in the pressing operation. I I I I As I have already stated, my slats are arcuate or convex in cross-sectional configuration and to.

obtain this shape I simply make use of a male I and female die of a corresponding shape, these dies beingsuitably secured in a press 5 one belowthe other. It is immaterial whether the male or convex die is secured to the bed 6 ,of the press or whether the female or concave die is so secured, as the alternate sheets of press paper and wax covered board maybe built up in the alternate arrangement already described upon either the female or the male die.

The glue impregnated sheets of press paper remain inthe press for eight hours during which timethe glue is forced well into the paper, the efliciency of this action being increased due to the fact that the sheets of press paper are curved in cross sections which has the effect of opening one side of the sheet while closing the other side. When taken out of the press, the glue im- 1 pregnated sheets are slats of a hard and smooth surface and possess considerable rigidity in themselves, apart from the additional rigidity obtained E through :the cross-sectional curvature thereof. They are nowplaced upon dryers which further improve the finish.

When dry, the slats are painted withan application of oil paint of good quality and body whereupon they are ready to be formed into a tection claimed to thisarticle of manufacture alone since it is obvious that many articles of manufacture may be made with paper treated in the foregoing manner. Furthermore, I do not confine myself to the use of red press paper as other papers "may 'be found equally suitable. Moreover, other flexible materials apart from paper may prove suitable such as textiles, felt and the like. I

Since various modifications canv be made in the above invention, and many apparently widely different embodiments of same, made within the scope ,of the claim without departing from the spirit and scope thereof, it is intended that all matter contained in the accompanyingspecification shall be interpreted as illustrative only and not in a limiting sense and I desire only such limitations placed thereon as are specifically expressed in the accompanying claim.

What ,I claim as my invention is:

In the manufacture of convex Venetian blind slats, the process which consists in steeping strips of press paper previously cut into strips of the desired length and width for approximately fifteen minutes in a solution of animal glue and water mixed in the proportion of approximately one pound of glue to one gallon of water, after- 7 wards placing one of said strips upon a cardboard slat coated with parafiin Wax, said slat having previously been placed upon a die, then superimposing alternate slats and strips upon the lowermost strip to a desired height so that a slat is at the apex of the pile so formed, then exerting pressure upon said strips and slats to squeeze the same together by means of a die in bearing engagement with the topmost slat, one of said dies being concave and the other convex to impart a convex cross-sectional configuration to said strips and said slats, said strips and said slats being maintained in a state of pressure between said dies for a period of approximately eight hours during which period the said solution of animal glue and water will be forced into the cells of said strips. CLARE G. YOUNG. 

